The sweetness of salsify root is a great match for the earthy flavour that mushrooms bring to a dish. Unfortunately, salsify is often hard to come by because it's so difficult to harvest, but if you can't find any, celeriac is a perfectly acceptable substitute. The herb mayo brings everything together, so don't leave it out – make your own, or just add chopped parsley, tarragon and dill to a good commercial variety. Serves four.

Put the pearl barley in a small saucepan, cover with plenty of water and boil for 30-35 minutes, until tender but still with a bite. Drain in a fine sieve, shake to remove all the water and transfer to a large bowl.

Wipe clean the barley pan, pour in three tablespoons of oil and place on a medium heat. Shave four strips of skin off the lemon and add to the hot oil, along with the garlic. Cook for a minute or two, stirring, just until the garlic turns light-golden, then tip over the barley, season and stir.

Clean the saucepan once more and squeeze in the juice of half the lemon. Add plenty of cold water and some salt. Peel the salsify with a potato peeler, cut on an angle into 3cm-long chunks and transfer immediately to the pan to avoid discolouration. Put the pan on high heat, bring to a boil and simmer for 20-25 minutes, until tender. Drain, and add to the barley.

Next, heat half the remaining oil in a large frying pan and add half the mushrooms. Cook on high heat for about two minutes, stirring once, to give the mushrooms a nice, golden colour. Add to the bowl of barley and repeat with the remaining oil and mushrooms.

Finally, add the parsley and tarragon, and squeeze in the juice of the remaining lemon half. Season to taste, and serve hot or warm with a dollop of herb mayonnaise.